Lightweight Scalarworks Mount for RMR

I have been a willing spectator (and participant at my day job) in the pursuit of reducing weight from firearms. Armed with billet, companies are using CNC machines and a bit of engineering to remove in many cases over 95% of the base billet into some truly unique products.

Taking advantage of the computer and CNC combination is Scalarworks, who’s previous release for the already low-weight Aimpoint T2 was well-received. Uping the ante and dropping the weight is their new mount for the Trijicon RMR. The mount is a scant 1.27 ounces. Total weight with the optic is 2.5 ounces.


While a few dedicated mounts may be slightly lighter, the new Scalarworks LDM/RMR is the lightest quick-detach option on the market. The Q/D is valuable for those wanting to use non-canted back-up iron sights. If the main optic broke, was fogged, or otherwise unusable, it would need to be removed.

The LDM/RMR is manufactured from 7075-T6 aluminum and includes their “recoil-proof” notched thumscrew and ball detent system. Scalarworks claims a “repeatable zero” so long as the LDM is mounted in the same place.

Pricing is set at $149 for the mount. Both absolute and lower one-third mounts are available. Put another way, the mount is little over $100 / ounce.



MATERIALS: 7075-T6 Aluminum Alloy / 4140H Steel Alloy
FINISHES: Mil-A-8625 Type III Hard Coat Anodizing / Black Nitride™
WEIGHT: 34.3g (1.21oz) LDM400 / 35.6g (1.26oz) LDM410 + 1.8g (0.06oz) SCREWS
WARRANTY: Lifetime

HEIGHT OVER RAIL (OPTIC CENTER): 36mm (1.42″) LDM400 / 40mm (1.57″) LDM410
COMPATIBLE FIREARMS: AR-15, AR-10, SCAR, Tavor and similar with MIL-STD-1913 Picatinny Rail

Nathan S

One of TFB’s resident Jarheads, Nathan now works within the firearms industry. A consecutive Marine rifle and pistol expert, he enjoys local 3-gun, NFA, gunsmithing, MSR’s, & high-speed gear. Nathan has traveled to over 30 countries working with US DoD & foreign MoDs.

The above post is my opinion and does not reflect the views of any company or organization.


  • CS

    The question still remains, will it hold or return to zero?

    • Kyle

      Yes and I haven’t tried it respectively. I ordered one of these the day they released.

    • Bob Oblog

      The way it’s mounted in the first photo it won’t.

    • Peeholestinger

      I think they have a video on their website of them testing the CompM4 mounts ability to return to zero. Doesn’t seem to be an issue.

  • Jtrain

    In the near future, when direct laser metal sintering is commercially viable, we will be shaking our heads at how much machining was being done to make these types of parts and the resulting cost.

  • plumber576

    Scarlaworks is really making some great stuff lately.

  • valorius

    $149 for a mount. LOL.

    • iksnilol

      Something something your mother something something.

      I know, low hanging fruit, but times are though.

      • valorius

        Primary arms makes a nice AR 1″/30mm mount that’s about $20 more than the generic version of the same mount. My brother has the PA mount, so i bought the generic to compare- they are identical. Both the name brand and generic mount work very nicely.

        • iksnilol

          PA makes good stuff from what I’ve read. + it fits my budget so to save a couple of grams weight, I doubt I’mma drop 100 bucks more.

  • egghead

    i have one of there mount/bundles for the MRO. very well made and maintains zero no problem taking it on and off 10+ times.

  • Wingbert

    Is there a chance the track could bend?